Roller cutter



Feb. 14, 192s.

C. H. M. BULL ROLLER CUTTER Filed March 28, 1927 Patented Feb. 14, 192s.

UNITED STATES PATENT OFFICE.

CLINTON E. M. BULL, OF HOUSTON, TEXAS, ASSIGNOR TO REED ROLLER BIT GOM- PANY, F HOUSTON, TEXAS, A CORPORATION 0F TEXAS.

ROLLER CUTTER.

Application filed March 28, 1927. Serial No. 178,987.

This invention relates to roller bits Jfor use in deep Well drilling, and more partie* ularly to roller cutters adapted to be mounted in said bits.

rlhe object of the invention is to provide a roller cutter having a removable point section which can be replaced when worn.

A further object of the invention is to provide a roller cutter with teeth thereon havingan efficient cutting operation.

Another object of the invention is to provide a new and improved mounting for roller cutters.

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Various other objects will be apparent from the following description:

rl`he preferred embodiment of the invention is illustrated in the. accompanying drawings, in which Fig. l is a side elevation of the cutter, and Fig. 2 a sectional view thereof.

Referring specifically to the drawings., the hit head is indicated at l, and has a recess :2 in the outer face thereof and a bore El leading inwardly from said recess and adapted to reeei\e `spindle 4, spindle 4 being secured in the head by nut 4, Head l is also provided with an annular flange 5 projecting inwardly adjacent the inner end of bore 3. V

'l` he base section 6 of the cutter is mounted on the head, and has a central opening (3 lo receive annular flange 5, a bushing 7 being interposed therebetween. Base section (l is provided with a recess 6" to receive the enlarged portion 4b of spindle 4 and the annular flange 8il of point section 8.

Annular flange 8 forms a recess in point section 8 to receive the end of spindle 4, and has a plurality of screw-threaded bores 8", to receive screw-threaded pins 9, said pins being adjustable inwardly into groove 4c, in spindle 4, to rotatably lock the point section on spindle 4 and in the recess 6b of base section 6. Annular flange 8 of point section 8 fits snugly in recess 6'? of base sect-ion 6 so that it is firmly supported laterally by the walls of recess 6" and longitudinally by the enlarged portion 4b of spindle 4, but at the same time is free to revolve. The engagement of pins 9 in groove 4 serves merely to prevent point section 8 from slipping out of base section 6 when the bit is not in use or when it is being lowered in or removed from the hole. 'When the bit is operating upon the bottom of the hole, the

pressure against it serves to hold the point section in place.

Spindle 4 has a key 4d. Bushing 7 and annular flange 5 have slots 7a and 5a, respectively, intowhich key 4d enters to prevent rotation of spindle 4 and bushing 7.

Teeth 8 of point section 8, as shown, are formed out of alinement with the teeth on base section 6, and larger than would be the teeth on the corresponding point portion of a single piece cutter with teeth converging from base to apex. Point section 8, immediately at the apex thereof, has four teeth 8d. The number and arrangement ofthese teeth may, of course, be. varied. The specific form shown, however, being the preferred embodiment.

The assembly and features of the elements constituting the invention, may be outlined as follows Bushing 7 is first placed upon annular flange 5. Base section 6 is then slipped upon said washer.

The end of spindle 4 is inserted in the recess in point section 8 formed by flange 8, and pins 9 are screwed inwardly so that the inner ends thereof enter groove 4c in spindle 4. Bores 8" and pins 9 have cooperating reduced portions, as shown, whereby the inward movement of pins 9 is so limited as to prevent frictional contact thereof with the bottom of groove 4c. The ends of flanges 8 are now immediately adjacent but not in frictional contact with enlarged portions 4" ot' spindle 4.

Spindle 4 with point section 8 mounted thereon is then slipped outwardly through base section 6 and bore 3 of head l, and nut 4 is screwed onto the screw-threaded end thereof to lock it in the head.

lVhen spindle 4 was thus inserted, key 4d thereof entered slots 5ft and 7a of flange 5 and bushing 7, respectively to lock spindle 4 and washer 7 against rotation When spindle 4 was drawn by nut 4, enlarged portion 4b was brought tightly against flange 5 and bushing 7, and loosely in contact with base section 6 to rotatably hold the same in position. Flange 8L of point section 8 entered recess 6b in base section 6 to gain a strong lateral support, and be rotatable ing action and the teeth of such cutters become so badly worn near the point. of the cutter, where they are smaller than at the base, as to seriously impair the operation of the bit, that portion of the teeth near the base remaining comparatively sharp. Cutters thus worn must be thrown away. The invention provides removable point sections which can be replaced when worn, the old base sections being used with the new point sections. And that the oint sections may wear less rapidly and per orm more efficiently, the invention provides teeth thereon of comparatively greater size. The placing of these teeth out of alignment with the teeth on the base section produces a more effective disintegration of the material encountered, and also serves to prevent material in the valleys of the teeth moving outwardly from entering the valleys of the teeth on the base section.

It will be noted further that base section 6 and oint section 8 are rotatable independent y of each other, and will therefore rotate according to the respective pressures upon them.

The invent-ion as dened in the claims is not limited to the specific tion illustrated and described.

I claim:

l. In a rotary boring drill', a spindle having an enlarged portion and a roller cutter having a base sectionl and a point section, said base section resting against the inner face of said enlarged portion, section resting against the outer face of said enlarged portion and being `rotatably secured to 'said spindle.

2. In a rotary boring drill, a spindle having an enlarged portion and a roller cutter having a base section and a point section, said base sect-ion having` a recess against the bottom of which said enlarged portion rests, and said point section resting on the enlarged portion and having a recess in which the end of the spindle is rotatably secured.

3. In a rotary boring drill, a head having an annular and slotted flange projecting therefrom, a spindle removably secured in vSaid head and having a. key fitting in the slot of said flange and an enlarged portion resting on said flange, a roller cutter havfollowing construcand said point messie ing a base section and a point section, said base section being rotatable on said. dange and resting against said enlarged portion, and said point section being mounted on said spindle and resting against said enlarged portion.

4. In a rotary boring drill, a head having a bore and an annular flange, a roller cutter having a base section and a .point section, said base section having an opening to receive said flange, and a recess, said recess being of such depth that the end of the annular flange projects above the plane of the bottom of said recess, and a spindle fitting in said bore and having an enlarged portion to bear against said flange, sain point section fitting within said recess and resting against said enlarged portion.

5. In a rotary boring drill, a head having a bore and an annular slotted flange, a roller cutter having a base section and a point section, said base section having an opening to receive said flange, and a recess, a spindle fitting in said bore and having a key resting in the slot of said flange, said point section being rotatably and removably secured in said recess.

6. In a rotary boring drill. a head having a bore and an annular sloted flange, a slotted bushing surrounding said flange, a roller cutter having a base section and a point section, said base section having an opening to receive said flange and bushing, and a recess, a spindle fitting in said bore and having a key resting in the slots of said flange and bushing, said point section being rotatably and removably secured in said recess.

7. In a rotary boring drill, a head having a bore and an annular flange adjacent said bore, said vannular flange being diametrically slotted, a spindle resting in said bore and having a transverse key fitting in the slot of said flange, and a roller cutter mounted on said spindle.

8. In a rotary boring drill, a head having an annular flange thereon, a bushing on said flange, said flange and bushing bemg slotbushing.

CLINTON H. M. BULL. 

